JPS6173275A - Device for reproducing recording disk information - Google Patents

Abstract

PURPOSE:To easily output information of two systems under an optional combination, by providing output terminals of two systems, each of which is composed of a pair of output terminals, of a recording disk, on which digital signals are recorded, and selectively switching information outputted from the output terminals. CONSTITUTION:By providing a pair of changeover switches 75A and 75B to two sets of output terminals and appropriately switching the switches 75A and 75B, audio signals can be outputted from the two sets of output terminals 73L and 73R and 74L and 74R under various combination. When, for example, the switches are simultaneously switched, audio signals of an analog system and digital system can be inverted between the output terminals 73L and 73R and output terminals 74L and 74R and, when both the switches 75A and 75B are separately switched, audio signals of the analog system and digital system can be outputted simultaneously from the two sets of output terminals 73L and 73R and 74L and 74R.

Description

TECHNICAL FIELD The present invention relates to a recording disc information reproducing apparatus, and more particularly to a reproducing apparatus for reproducing recorded information on a recording disc on which digital signals are recorded.

As a recording disk on which a digital signal is recorded, a so-called compact disk (hereinafter abbreviated as CD), which is a digital audio disk in which an audio signal is subjected to predetermined digital modulation processing and recorded as a pulse train, is known. Furthermore, recently, a method has been developed in which a pulse train signal obtained by digitizing an audio signal using a predetermined digital modulation method is superimposed on each FM modulated signal of a video signal and an audio signal (refer to the specifications of Japanese Patent Application No. 58-45780). A video disc (hereinafter abbreviated as LDD) has been developed.

In this recording system, the audio signal is made into two channels, and the 2.3 MH2 and 2.8 MHz audio carriers are each FM-modulated by two audio channel signals. The video signal is frequency-converted so that the sync tip is 7°6 MHz, the pedestal level is 8.1 MHz, and the white beak is 9.3 MHz. Then, the audio signal is further converted into PCM (Pulse Code Modula).
The signal is digitized and converted into a pulse train signal using a modulation method such as 2000-2000.

This pulse train signal is, for example, an EFM (Eight to
The signal is suitable for recording using the "ourteen modulation" method, and the frequency spectrum consists of frequency components of a pulse train with a width of 3T to 111-.Here, T indicates the bit period of the PCM signal, The pulse is approximately 720KHz, the maximum width is 11
The T-pulse has a frequency of approximately 200KHz. Such a pulse train signal is about 1/10 of the video main carrier.
The signals are superimposed at the following levels, sliced amplified at one corner nearest the zero cross, and pulse width modulated to become a recording signal.

RF (8 frequencies) obtained from a recording disk on which video signals and audio signals are recorded using the above recording method.
The frequency spectrum of the signal is as shown in FIG. In Fig. 1, the component denoted by A is a digitized audio signal component, the component denoted by B is an audio FM signal component, the component not denoted by C is a color information component added to the video FM component, and the component denoted by D is a digitized audio signal component. This is a luminance information component in a video FM signal.

Since the dynamic range of the digitized audio signal can be approximately 90 dB or more, the sound quality can be significantly improved compared to recording and reproducing audio signals using the FM modulation method.

In this way, LDDs have the characteristic of being able to record audio in two systems, analog and digital, and it would be extremely convenient if these two systems of information could be output in any combination during playback. , and the range of its application can be expanded.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a recording disc information reproducing device that can easily output two types of information in any combination.

The recording disc information reproducing device according to the present invention has a video (8
2 sets of outputs, each consisting of a pair of outputs, each of which is capable of reproducing a recording disc on which a predetermined digital signal and a predetermined modulated signal and a predetermined digital signal are superimposed. A terminal, a specifying means for specifying the type of information to be output from each of these two sets of output terminals, and a demodulated output of a reproduced audio signal and a demodulated output of a reproduced digital signal are inputted, and each of these demodulated outputs is inputted to the specifying means. The apparatus is characterized by comprising a switching means for supplying the two sets of output terminals in combination based on the output.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 2 is a block diagram showing an embodiment of a recording disc information reproducing apparatus according to the present invention. Such a reproduction position is l-
This is a so-called compatible player that can play D, CD, and DD. As mentioned above, this player has different playback speeds for video discs (LD, LDD) and digital audio discs (CD).
A spindle motor 1 for driving an LDD rotation and a spindle motor 2 for driving a CD rotation are provided. These spindles 1 and 2 are selected depending on the type of f-isk to be reproduced j1°1, and are switched by a switching groove 4 using, for example, a motor 3 as the fh source.

In order to detect the disc size of the disc 5 to be reproduced, for example, three detection sensors 6, 7 and 8 are provided corresponding to the disc size in the disc radial direction. The disc size for CDs is approximately 5 inches (1
2 cm>, and in the case of video discs (LD, LDD), there are two types of outer diameters: 8 inches and 12 inches. The outputs of the three detection sensors 6 , 7 and 8 are waveform-shaped by a waveform shaping circuit 9 and then supplied to a disk discrimination circuit 10 . As the detection sensor, for example, an optical sensor is used, but the detection sensor is not limited to this.

The disc discrimination circuit 10 determines whether the disc to be played is a CD or an LDD based on the detection outputs of the detection sensors 6.7 and 8.
It is determined which of the three types of disks, LD and LD. The specific circuit configuration of this disk discrimination circuit 10 is shown in FIG. In this diagram, in the case of CD,
The disc size is determined to be the minimum (12 cm), and the detection output of the innermost detection sensor 6 and the inverter 79.8
A where the inverted output of the detection sensor 7.8 that has passed through 0 is made by 3 people
The output of the ND gate circuit 78 becomes CD discrimination information. That is, when the detection sensor 6 is on and the other detection sensors υ7 and 8 are off, it is determined that it is a CD. In the case of a video disc, since the disc sizes are 8 inches and 12 inches, the detection output of the detection sensor 7 or 8 passes through the OR gate circuit 69 and becomes the output of each of the AND gate circuits 70 and 71. Further, a frame synchronization detection signal generated when a frame synchronization signal is detected from a frame synchronization detection circuit 21 (to be described later) becomes another input to the AND gate circuit 71, and is inverted by an inverter 72 to the AND gate circuit 70. It can also be used as another input. When the detection output of the detection sensor 7 or 8 is generated and the frame synchronization detection signal is input, the AND gate circuit 71 outputs LDD discrimination information, and when the frame synchronization detection signal is not input, the AND gate circuit 70 outputs the LDD discrimination information. Discrimination information is output.

This discrimination information is used to drive an indicator 11 that displays the type of disc, and as a switching signal for various switches to be described later.

A pickup 12 for reading recorded information from the disk 5 is carried by a slider base (not shown) that is movable in the radial direction of the disk 5, and the slider base is driven by a slider motor, a reduction gear, etc. 8. Driven by a motor (not shown). Read information read from the recording disk 5 by the pickup 12 is supplied to a digital information demodulation system 14, an analog audio demodulation system 15, and a video demodulation system 16 through an RF amplifier 13, respectively. The RF amplifier 13 supports a wide band of approximately 5KH2 to 14MHz, and is capable of amplifying a reproduced PCM audio signal, a reproduced FM audio signal, and a reproduced video signal with a single 7-band amplifier.

In the digital information demodulation system 14, f
! A #J changeover switch 17 is provided, which changes depending on the type, and this switch 17 is set to a in the case of an LDD based on the disk information from the disk discrimination circuit 10 mentioned above.
In the case of a CD, it switches to the a side. That is, L
The signal processing system for the reproduced digital signal is switched between DD playback and CD playback. When playing a CD,
The playback RF output is PCM audio information, and this PC
The M audio information is M T F (Modulation
nTransfer Function ) compensation is applied.

On the other hand, in the case of LDD, FM audio information and FM
PCM audio information included in the reproduced RF signal along with video information is extracted by an LPF (low pass filter) 19 and supplied to a de-emphasis circuit 20. PC
M audio information is, for example, an EFM signal, but if the digital signal is directly superimposed on an FM-modulated video signal during recording, the digital signal component will be FM-modulated.
Since this will be interfered with by the low frequency components of the video signal, the low frequency components are boosted and recorded. Therefore, during reproduction, the de-emphasis circuit 20 performs compensation by dropping the low-frequency components boosted during recording. This makes it possible to improve the S/N ratio of the digital signal with respect to low frequency noise during recording and reproduction.

Note that instead of switching the signal processing system using the changeover switch 17, the power supply to each signal processing system circuit is set to 0N.
A similar effect can be obtained by using 10FF.

The reproduced EFM signal that has passed through the changeover switch 17 is supplied to the EFM demodulation circuit 22 via the frame synchronization detection circuit 21 and is also supplied to the reproduced clock extraction circuit 23. The EFM demodulation circuit 22 demodulates the signal into a PCM digital signal.

This demodulated signal is input to a memory controller 25 such as RAM (Random Access Memory), etc. under the control of the memory controller 25. At this time, the memory controller 25 uses a write clock which is the frequency-divided output of the reproduced clock by the frequency divider 26. Writing is performed in synchronization with .

Reading of stored information from the memory 24 is performed in synchronization with a read clock obtained by dividing the oscillation output of a VCO (voltage controlled oscillator) 27 in a PLL (phase locked loop) circuit by a frequency divider 28. It looks like this. The PLL circuit is the VCO27 mentioned above.
, the frequency division output of the reproduced clock by the frequency divider 29 and the VCO2
A phase comparator (P/C) 31 which uses the divided output of the frequency divider 27 of the oscillation output of No.
The output voltage of 2 and the reference voltage Vref+ are selectively set to VC.
It is constituted by a changeover switch 33 for supplying to O27.

In the PLL circuit, the changeover switch 33 is set to the a side and output voltage of the LPF 32 during LDD playback, and is switched to the b side during CD playback, based on the discrimination result of the disk discrimination circuit 10 described above, so that the output voltage of the LPF 32 is set to the base Q=lightning voltage rer+. VC
Supplied to O27. As a result, during LDD playback, the readout clock for reading stored information from the memory 24 is synchronized in phase with the playback clock by the P L 1 circuit, and during CD playback, the phase of the readout clock for reading stored information from the memory 24 is synchronized with the playback clock.
When turned on (closed), the output of the phase comparator 31 drives the CD rotation drive spindle motor 2 through the LPF 77, so that the reproduced clock is phase-synchronized with the fixed clock obtained by the VCO 27 whose bias is in a fixed state. It turns out.

The digital signal thus read out is converted into an analog audio signal by a D/Δ (digital/analog) converter 34, and then sent to an LPF 35L.

35R to become left and right playback audio outputs.

The usage status in the memory 24 is constantly monitored by the memory controller 25, and when the memory 24 overflows or becomes blank (no data), the controller 25 receives the information and sends the information to the voltage generator 36. When the LDD is re-coupled, this voltage generator 3
6, in accordance with information indicating the usage status of the memory 24 from the memory controller 25, "[controls] lightning voltage when the memory 24 overflows, and a negative control voltage when the memory 24 becomes blank." The frequency of the read clock is controlled by supplying the output voltage of the LPF 32 to the VCO 27 via the selector switch 33.

In this way, the amount of data stored in the memory 24 is constantly monitored, and when there is an excess or deficiency in the capacity and processing capacity of the memory 24, a positive or negative control voltage is generated to cause the PLL circuit to deal with the problem. By requesting this, the memory 211 can always be maintained in a normal state.

In the analog audio demodulation system 15, the outputs of BPFs (band pass filters) 37L and 37R that pass only the 2.3 MHz and 2.8 MHz A-diox rear components from the reproduced RF signal are sent to FM demodulators 38L and 38R.
t: FM demodulated and de-emphasis circuit 3
Left and right playback audio outputs are provided via 9m and 39R.

In the video demodulation system 16, the reproduced RF fffi signal is B
Only video information is extracted by the PF&notch circuit 4o.

In this BPF & notch circuit 40, the EFM components included in the reproduced RF signal and 2.3 MHz, 2.
．． The 8MHz audio carrier component is actively removed. This extracted information is the limiter circuit 41
The signal is supplied to the F~1 demodulator 42 via FM demodulation.

This demodulated output is passed through LPF 43 with dropout compensation (
It is supplied to f[1(DQC) 44, and dropout compensation is performed in the compensator 44. This dropout compensator 44 includes, for example, a dropout sensor (008) that detects a dropout based on a reproduced RF signal supplied via an HPF (bypass filter) 45.
46, and a hold capacitor provided between the switch output terminal and a reference potential point. Therefore, when a dropout occurs, the dropout sensor 4
The output level of the LPF 43 immediately before the occurrence of the drop error 1 to the compensator 44 is held and sent to the next stage circuit, and the dropout compensation is performed. becomes.

The output of the dropout compensator 44 is also supplied to a horizontal synchronization component 1 circuit 47, and a horizontal synchronization signal is separated and output. This horizontal synchronizing signal is supplied to phase comparators 48 and 49, and the phase difference with the reference signal output from the reference signal generator 50 is detected. The output of the phase comparator 48 serves as an input to the adder 51, and the outputs of the four phase comparators serve as other inputs to the adder 51 via the equalizer 7 amplifier 52. The output of the adder 51 drives the LDD and the spindle motor 1 for driving the rotation of the LD via an equalizer amplifier 53 and a driver 54. This is the spindle servo system. Further, the output of the equalizer amplifier 52 is connected to a loop switch 55,
An actuator (not shown) built into the pickup 12 is driven via the changeover switch 56 and the driver 57.

By driving this actuator, the optical spot for reading information is directed in the tangential direction of the recording track of the disk. This is a tangential servo system. It may also be a tangential mirror that tilts the light spot for reading information in the tangential direction of the recording track of the disk, or a tangential mirror that tilts the light spot for reading information in the direction perpendicular to the optical axis. A configuration in which the spot is moved in the tangential direction of the recording track of the disk may also be used.

The loop switch 55 is turned on (opened) in response to a spindle lock signal output from the spindle lock detection circuit 58 when locking of the spindle servo system is substantially completed. That is, at the start of playback, the spindle motor 1 is first driven by the output of the phase comparator 48 to perform rough adjustment of the time axis (spindle servo).
When the locking of the spindle servo is substantially completed, the loop switch 55 is turned on, and the actuator is driven by the outputs of the four phase comparators to perform fine adjustment of the time axis (tangential servo).

According to this, residual jitter components that cannot be removed by the spindle servo system can be removed by the tangential servo system.

However, even in the tangential servo system, jitter cannot be completely removed because IA mechanical systems such as actuator drive line drawing cannot sufficiently follow high-frequency components of residual jitter. Therefore, in the digital information demodulation system 14 mentioned above, P
By setting the cutoff frequency of the LPF 32 of the LL circuit to be lower than the large frequency of the tangential-charmy-volume band, the high-frequency components of the residual jitter are cut.
This means that residual jitter components can be removed. More preferably, by setting the cutoff frequency of the 1PF 32 lower than the disk eccentricity frequency (30 to 8 Hz in the case of an LDD), it is possible to completely eliminate jitter caused by disk eccentricity.

Although the spindle servo and tangential servo were performed based on the horizontal synchronization signal, the same effect could be obtained by performing the spindle servo and tangential servo based on the 3,58 Ml-1z color subcarrier included in the reproduced FM video signal. It will be done.

The above is a servo system when reproducing a video disc (LDD, LD), but when reproducing a CD, spindle servo is performed based on the output of the phase comparator 31 in the digital information demodulation system 14 described above. That is,
The output of the phase comparator 31 drives the spindle motor 2 for driving the CD rotation via a loop switch 59 that is turned on (closed) during CD reproduction and a driver 60. Conventionally, the above-mentioned tangential servo was not performed during CD playback, but since the spindle motor 2 cannot sufficiently follow the high frequency component of the output signal of the phase comparator 31, which is a time axis error signal, this In the example, HPF6
The high frequency component of the time axis error signal extracted by 1 is
A servo that drives an actuator within the pickup 12 via a changeover switch 56 and a driver 57, that is, a tangential servo, is also employed. The changeover switch 56 is set to the a side when playing an LDD or LD, and to the b side when playing a CD, based on the discrimination result of the disc discrimination circuit 100.
Switch to ll111.

Note that the tangential servo during CD reproduction is performed based on the frequency-divided output of the reproduction clock extracted by the reproduction clock extraction circuit 23.

If this is done based on the frequency-divided output of the frame synchronization signal detected by the frame 11JI detection circuit 21, the same effect can be obtained since the frame synchronization signal and the reproduced clock are in a synchronous relationship.

The output of the spindle lock detection circuit 58 is connected to the inverter 62.
This signal is inverted and becomes the sole power of the OR gate circuit 63 as a spindle unlock signal indicating that the spindle servo system is not in the locked state.

As another input to the OR gate circuit 63, a random access information signal generated at the time of a random access command such as scan, search, jump, etc. is supplied. The OR goo 8 circuit 63 also receives the LDD information output from the disk discrimination circuit 10.

The output of the OR gate circuit 63 is supplied to the recovered clock extraction circuit 23 via the control command circuit 64.

A specific circuit configuration of the recovered clock extraction circuit 23 is shown in FIG. In this figure, the reproduced EFM signal is transmitted to the phase comparator 6.
5, the phase difference with the oscillation output of vCO (voltage controlled (21) oscillator) 66 is detected, and the phase difference signal is sent to LPF 6.
7 and a changeover switch 68 to the VCO 66 . As described above, a PLL circuit that generates a reproduced clock is configured.

The changeover switch 68 is normally located on the a side and supplies the output of the LPF 67 to the VCO 66, but the control command circuit 6 described above
When a command signal is output from 4, it switches to the b side in response to this command signal and sets the predetermined reference voltage ■r'ef2.
is supplied to the VCO 66.

That is, when the spindle servo is not in a locked state or when the information reading optical spot jumps tracks due to random access commands such as skid, search, jump, etc., the reference voltage Vrcrz is applied to the VCO 66 to reproduce its oscillation frequency. By fixing the clock frequency to a value close to the clock frequency, it is possible to hasten the lock-in of the recovered clock after the spindle servo is locked or after the random access command is released.

Referring again to FIG. 2, the audio output section includes a pair of left and right output terminals 73L and 73R of the analog audio output system.
A pair of left and right output terminals 74L and 74R of a digital audio output system are provided. Output terminal 73L,
73R has analog audio! Audio output from the J key system 14 is provided. This audio output is LD
During playback, the output terminal 74L,
Also supplied to 74R. The changeover switch 5 inputs the audio output from the analog audio demodulation system 14 and the audio output supplied from the digital information demodulation system 14 via the left and right mode changeover switches 76L and 76R, and sets the normal state during LD playback, for example. Place it on the a side as
The control means 82 inputs the output of the mode specifying means 81 which specifies the output mode by the changeover switch 75, for example, analog only or auto digital (digital audio is Kunimitsu), and the LDD and CD disk discrimination information from the disk discrimination circuit 10. Switching is controlled by This control means 82 switches the changeover switch 75 to the b side when playing a CD regardless of the output of the mode specifying means 81, and keeps the changeover switch 75 to the a side when the output of the mode specifying means 81 is analog only when playing an LDD. , in case of auto digital, to switch to side b.
ill ian Vru.

As a result, during LD playback, the output terminal 73L.

Normal audio signals are output from 73R and output terminals 74L and 74R, and when playing a CD, output terminals 74L and 74R are output.
A high-quality audio 71 transmission is output from 74R, and the LD
During D playback, if the mode specified by the mode specifying means 81 is analog only, the output terminal 73 is used as in the case of LD playback.
Normal A-dio signals are output from both m and 73R and output terminals 74L and 74R, and in the case of auto digital, normal audio signals are output from output terminals 73L and 73R, and high quality audio signals are output from output terminals 74L and 74R. An audio signal will be output.

In the above example, the changeover switch 75 was provided corresponding to the output terminal 74L, 741 on the back side of the two-phase output terminal, but as shown in FIG. , 2Il
A pair of selector switches 75△, 75 correspond to the output terminals of
By providing the selector switches 75Δ and 75B as appropriate, the output terminals 73L and 73 of the 2111
R and output terminal 74L.

Audio signals are output from 74R with divine combinations.
can be done. For example, selector switch 75, to 75
By switching B at the same time, each audio No. 13 of the analog system and f digital system is output to the output terminals 73L and 73.
R and output terminals 74L, 74R, and by switching both switches 75Δ, 75B separately, two sets of output terminals 73L, 73R and output terminal 74L.

It is also possible to simultaneously output analog or digital audio No. 418 from the 74R.

The mode changeover switches 76L and 76R are provided to change over the output mode of digital audio audio signals in an analog stage. That is,
If the audio output from the digital audio demodulation system 14 is stereophonic, the above-mentioned output mode will suffice, but in the case of audio multiplexing, for example, the L (left) channel is Japanese and the R (right) channel is a foreign aB. There are 77PtJ! modes that operate independently of each other.
Output terminals 74L and 7 are controlled by switches 76L and 76R.
The audio output from 4R is Japanese, foreign language, and Japanese language.
It is possible to switch between three output modes: i only and foreign language only. mode selector switch 76L,
The driving of 76R is performed separately according to control information from the illustrated operating section.

Relays that operate independently are used as the mode changeover switches 76L and 76R. Normally, a relay with one movable contact and two fixed contacts is sufficient for signal switching, but in this embodiment, one additional movable contact and two fixed contacts are used. A relay is used. That is, if we take the relay 76 on the 1-dilennel side as an example, there are two sets of movable contacts Sl+ that interlock with each other.

52+ and this 2II possible a)? Two sets of fixed contacts S12., one pair for each point So and S2+ are provided. +3,
S;2, ):l, etc., and the two fixed contacts S+2, which are the most distant from the two sets of fixed contacts. , S23 serve as input ends for the two signals (left audio output), and one movable ratio point Su serves as an output end. According to this, since there are two gaps between the left and right signal lines, it is possible to reliably prevent crosstalk between the left and right signal lines. ] Of course, the stalk can be more reliably prevented from LL.

4jAlthough it is not shown in the figure, it>
Focus 1 Nervo system that controls the J position, and the radial direction of the disk of the pickup 12
Of course, a tracking servo system is also provided, and these servo systems also support video discs (
It is preferable to switch the signal processing system for error signals between LDD, LD) playback and digital audio disk (CD) playback, so that good servo can be performed regardless of the type of disk being played back.

In addition, the digital signal recorded on CD or LDD is
In addition to audio information, it also includes digitized image information, control information for the computer 11, and the like.

As described in detail of the invention, according to the recording disk information reproducing apparatus according to the present invention, output terminals for two systems each consisting of a pair are prepared, and the information outputted from these output terminals can be selectively switched. Therefore, it is possible to easily output two types of information in any combination, which is extremely convenient and expands the scope of its application.

[Brief explanation of the drawing]

Figure 1 shows the video signal, audio Δ(i:i:i) frequency modulated signal, and analog No. 15.
A diagram showing an RF multiplied signal frequency spectrum obtained from a recording disc in which M-modulated and pulsed signals are recorded with a small R. FIG. 2 shows an embodiment of the recording disc information reproducing apparatus according to the present invention. Show. 3 is a block diagram showing only one circuit configuration of the disk discrimination circuit in FIG. 2, and FIG.
FIG. 5 is a block diagram showing a specific circuit configuration of the reproduced clock extraction circuit in the figure, and FIG. 5 is a circuit diagram showing another embodiment of the Δ-Dio output system in FIG. 2. Explanation of symbols of main parts 1...Swiss spindle motor 2 for LD and LDD
...CD spindle motor 5 ... Recording disc 10 ... Disc discrimination circuit 12 ... Pickup 14 ... Digital information demodulation system 15 ...・−
・Analog audio demodulation system 16...Video demodulation system

Claims (1)

[Claims] A recording disc information reproducing device capable of reproducing a recording disc on which a video signal and an audio signal are respectively superimposed with a predetermined modulated signal and a predetermined digital signal, comprising two sets of output terminals each consisting of a pair; A designation means for designating the type of information respectively output from the two sets of output terminals, and a demodulation output of a reproduced audio signal and a demodulation output of a reproduction digital signal are input, and each of these demodulation outputs is based on the output of the designation means. A recording disc information reproducing apparatus comprising: switching means for supplying signals to the two sets of output terminals in combination.